Stability of Extemporaneously Compounded Domperidone 5 mg/mL Suspension in Oral Mix in Plastic and Glass Bottles and Plastic Syringes

Abstract

Domperidone liquid for oral administration is not commercially available in Canada, but is needed for patients who cannot swallow intact tablets. To evaluate the stability of domperidone 5 mg/mL suspensions prepared in Oral Mix vehicle and stored, for up to 91 days, in amber polyvinylchloride (PVC) bottles, amber glass bottles, or amber polyethylene terephthalate (PET) bottles at 4°C or 25°C or in polypropylene oral syringes at 25°C. Three separate 300-mL batches of domperidone suspension 5 mg/mL were prepared with Oral Mix vehicle. Fifty-millilitre aliquots of the suspension were stored in 100-mL bottles (amber PVC, amber glass, or amber PET). Half of the bottles of each type were stored at 25°C and half at 4°C. On study days 0, 1, 2, 4, 7, 10, 14, 21, 28, 35, 42, 49, 63, 77, and 91, domperidone concentration was determined, with a validated reverse-phase, stability-indicating liquid chromatographic method, in samples drawn from each type of container stored at each temperature. In addition, 1.5-mL aliquots of a fourth 100-mL batch of suspension were stored in 3-mL oral syringes at 25°C and were tested on the same study days. The concentration of domperidone in all study samples remained above 93% of initial concentration after storage for 91 days. The percent remaining on day 91, based on fastest degradation rate (as represented by the lower limit of the 95% confidence interval [CI]), was at least 92.3% for suspensions stored at 4°C in PVC, glass, and PET bottles. With storage at 25°C, suspensions in PVC and glass bottles retained more than 90% of initial concentration, whereas suspensions in PET bottles and plastic syringes retained 88.9% and 88.0% of initial concentration, respectively. Because suspensions of domperidone in PET bottles and oral syringes retained less than 90% of their initial concentration on day 91 (based on the 95% CI), it is suggested that such suspensions be stored at 4°C or 25°C in any bottle type or syringe with an assigned beyond-use date not exceeding 75 days.